What are the four compartments of a ruminant stomach?

The correct answer is based on the unique physiology of ruminant animals, which are specially adapted for digesting fibrous plant material. Ruminants, such as cows, sheep, and goats, possess a complex stomach structure that consists of four distinct compartments.

The first compartment, the rumen, serves as the primary fermentation chamber where microbiota break down cellulose and other complex carbohydrates found in plant material. The second compartment, the reticulum, works closely with the rumen in the digestion process, enabling the movement of food back to the mouth for rumination, or chewing the cud. The omasum, the third compartment, absorbs water and nutrients from the digested feed, while the fourth compartment, the abomasum, functions similarly to a monogastric stomach, producing digestive enzymes to further break down food.

This specific arrangement allows ruminants to efficiently process high-fiber diets, making them remarkably efficient at extracting nutrients from plant-based foods. The options that mention either the cecum, duodenum, or improperly list one of the four key stomach compartments do not accurately represent the structure of a ruminant stomach.